Lens adjustment

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Under lens adjustment (engl. Lensshift) also oblique projection means is a function of projectors referred to in which the lens can be adjusted to avoid a trapezoid distortion with optical means at an oblique projection.

Oblique projection, imaging rays


Lens adjustment is a function of projectors in which the lens can be moved parallel to the original projection (LCD, slide, etc.) for an oblique projection. As a result, an orthogonal representation on the projection template is also projected orthogonally onto the screen .

The objective of lens adjustment is to avoid trapezoidal distortion with optical means. This avoids the disadvantages of digital compensation, such as reduced resolution, staircase artifacts or reduced light intensity .

Oblique projection, illuminating rays

Depending on the design of the projector, the lighting unit must also be moved accordingly. As a result, the light source is shown in the center of the shifted lens. Not every lens is suitable for lens adjustment. The lens needs a large image circle for adjustment. Angled projection is possible for both horizontal and vertical use.

Work projector with lens and lighting adjustment


  • Film projection from the projection booth to the lower-lying vertical screen.
  • Video projection without losses due to digital compensation.
  • Work projection in training and teaching, angles or a curve shape are retained on the screen.

Individual evidence

  1. Wolfgang Grau: Technique of the projection. Beuth Verlag GmbH, Berlin 1994, page 488, ISBN 3-410-13194-9 .